The impact of disasters continues to grow in the early 21st century, as extreme weather events become more frequent and population density in vulnerable coastal and inland cities increases. Against this backdrop of risk, decision-makers persist in focusing primarily on structural measures to reduce losses centered on physical infrastructure such as berms, seawalls, retrofitted buildings, and levees. Yet a growing body of research emphasizes that strengthening social infrastructure, not just physical infrastructure, serves as a cost-effective way to improve the ability of communities to withstand and rebound from disasters. Three distinct kinds of social connections, including bonding, bridging, and linking social ties, support resilience through increasing the provision of emergency information, mutual aid, and collective action within communities to address natural hazards before, during, and after disaster events. Investing in social capital fosters community resilience that transcends natural hazards and positively affects collective governance and community health. Social capital has a long history in social science research and scholarship, particularly in how it has grown within various disciplines. Broadly, the term describes how social ties generate norms of reciprocity and trust, allow collective action, build solidarity, and foster information and resource flows among people. From education to crime, social capital has been shown to have positive impacts on individual and community outcomes, and research in natural hazards has similarly shown positive outcomes for individual and community resilience. Social capital also can foster negative outcomes, including exclusionary practices, corruption, and increased inequality. Understanding which types of social capital are most useful for increasing resilience is important to move the natural hazards field forward. Many questions about social capital and natural hazards remain, at best, partially answered. Do different types of social capital matter at different stages of disaster—e.g., mitigation, preparedness, response, and recovery? How do social capital’s effects vary across cultural contexts and stratified groups? What measures of social capital are available to practitioners and scholars? What actions are available to decision-makers seeking to invest in the social infrastructure of communities vulnerable to natural hazards? Which programs and interventions have shown merit through field tests? What outcomes can decision-makers anticipate with these investments? Where can scholars find data sets on resilience and social capital? The current state of knowledge about social capital in disaster resilience provides guidance about supporting communities toward more resilience.